System management method and apparatus for supporting non-dedicated

Abstract

A method is provided for creating a virtual operating system directed power management event. The method may include executing a prepare-to-sleep routine in a computer system running an Advanced Configuration and Power Interface (ACPI) compliant operating system. The prepare-to-sleep routine may include programming ACPI compliant core logic such as the Intel PIIX4 device to generate an I/O trap system management interrupt (SMI) upon accesses to the ACPI WAK.sub.-- STS register. The prepare-to-sleep routine may also enable non-dedicated event signals, such as legacy IRQs, to serve as resume events. After a resume event, the operating system reads the WAK.sub.-- STS register. Upon access to the WAK.sub.-- STS an SMI is generated. An SMI handler may be executed that determines if the resume event was generated by a wake device. If the resume event was in response to a non-dedicated event signal such as a legacy IRQ, the handler writes to a configuration register in the core logic which causes an unused dedicated event signal to appear as if it was asserted in the ACPI general purpose event register. Upon a subsequent access of the general purpose event register, the operating system will now recognize an ACPI compliant event. Alternatively, the core logic may be modified to include an event status/enable pair for each legacy IRQ.